AFTER ZAYN: WHAT'S NEXT FOR 1D?

The news that Zayn Malik is parting ways with SYCO/Columbia's One Direction has created much sturm und drang in the lad band's massive fan base. Malik's departure has been discussed by the band, management and label for some time, and officially 1D will continue as a quartet (their fifth album is due later this year and plans for the next leg of their gargantuan world tour continue). But questions surround the future of what may be the biggest boy band of all time: Will a JT-like solo star emerge from the group, or will it follow the trajectory of its predecessors, with a reunion tour a decade or so down the line?